duckling/sass/_nav.scss

#handle {
	position: fixed;
	z-index: 999;
	transition: var(--transition);
	margin: 0 auto;
	inset-block-start: 0;
	inset-inline-end: 0;
	inset-inline-start: 0;
	width: min(var(--container-width), 90%);
	height: 4.25rem;

	&::before {
		position: absolute;
		transition: var(--transition);
		margin: 0 auto;
		inset-block-start: 0.5rem;
		inset-inline-end: 0;
		inset-inline-start: 0;
		box-shadow: var(--edge-highlight);
		border-radius: 999px;
		background-color: var(--accent-color);
		width: min(calc(var(--container-width) / 4), 100%);
		height: 0.5rem;
		content: "";
	}

	&:hover::before,
	&:has(+ #site-nav:hover)::before,
	&:has(+ #site-nav *:focus-visible, + #site-nav *:focus)::before {
		transform: translateY(-1rem) scale(0.5);
		opacity: 0;
	}

	&:hover + #site-nav,
	& + #site-nav:hover,
	& + #site-nav:has(*:focus-visible, *:focus) {
		transform: none;
		opacity: 1;
		pointer-events: auto;

		&::before {
			-webkit-backdrop-filter: var(--blur);
			backdrop-filter: var(--blur);
		}
	}

	& + #site-nav {
		position: fixed;
		transform: translateY(-1rem) scale(0.5);
		transform-origin: top;
		opacity: 0;
		transition: var(--transition);
		margin: 0 auto;
		width: max-content;
		pointer-events: none;

		&::before {
			-webkit-backdrop-filter: saturate(1) blur(0);
			backdrop-filter: saturate(1) blur(0);
			transition: var(--transition);
		}
	}
}

#site-nav {
	grid-area: nav;
	margin: 1rem auto 0;
	inset-block-start: 1rem;
	inset-inline-end: 0;
	inset-inline-start: 0;
	border-radius: 1.625rem;
	max-width: min(var(--container-width), 90%);

	@media only screen and (max-width: 480px) {
		position: relative;
		margin: 0 auto;
	}

	&::before {
		position: absolute;
		z-index: -1;
		inset: 0;
		border-radius: 1.625rem;
		content: "";
	}

	nav {
		padding: 0.5rem;

		& > a {
			-webkit-backdrop-filter: var(--blur);
			position: absolute;
			left: 50%;
			transform: translateX(-50%);
			opacity: 0;
			z-index: 999;
			backdrop-filter: var(--blur);
			transition: var(--transition);
			inset-block-start: 0;
			box-shadow: var(--edge-highlight), var(--shadow-glass);
			border-radius: 999px;
			background-color: var(--glass-bg);
			padding: 0.625rem 0.75rem;
			pointer-events: none;
			line-height: 1;
			text-decoration: none;

			&:focus {
				opacity: 1;
				inset-block-start: calc(100% + 0.5rem);
			}
		}

		ul {
			display: flex;
			flex-wrap: wrap;
			justify-content: center;
			align-items: center;
			gap: 0.25rem;
			margin: 0;
			padding: 0;
		}

		li {
			display: flex;
			margin: 0;
			padding: 0;
			list-style: none;

			@media only screen and (max-width: 480px) {
				&:not(:has(.circle)) {
					flex: 0 0 100%;
				}
			}
		}

		a,
		summary {
			flex: 1;
			transition: var(--transition);
			box-shadow: none;
			border-radius: 999px;
			background-color: transparent;
			padding: 0.625rem 0.75rem;
			font-weight: bold;
			line-height: 1;
			list-style: none;
			text-align: center;
			text-decoration: none;
		}

		a.active {
			color: var(--accent-color);

			&:hover {
				color: var(--accent-color); ///
			}
		}

		#home a {
			color: var(--fg-muted-5);
			font-weight: 800;

			&:hover {
				color: var(--fg-color);
			}

			&.active {
				color: var(--accent-color);
			}
		}

		a,
		#language-switcher summary,
		summary {
			color: var(--fg-muted-4);

			&:hover {
				color: var(--fg-muted-5);
			}

			&:active {
				transform: var(--active);
			}
		}

		.circle {
			padding: 0.625rem 0.625rem;
			line-height: 0;

			&::before {
				display: none;
			}

			.icon {
				vertical-align: -0.125em;
				transition: var(--transition);
			}
		}

		button {
			appearance: none;
			transition: var(--transition);
			cursor: pointer;
			border: none;
			border-radius: 999px;
			background-color: transparent;
			font-size: var(--font-size-medium);
		}

		details {
			display: flex;
			position: relative;
			flex: 1;
			box-shadow: none;
			border-radius: 0;
			background-color: transparent;
			padding: 0;

			&[open] ul {
				animation: dropdown-open var(--transition);

				@keyframes dropdown-open {
					from {
						transform: scale(0.5) translate(-50%, -1rem);
						opacity: 0;
					}
				}
			}

			ul {
				-webkit-backdrop-filter: var(--blur);
				position: absolute;
				left: 50%;
				flex-direction: column;
				transform: translateX(-50%);
				transform-origin: top left;
				z-index: 1;
				backdrop-filter: var(--blur);
				inset-block-start: 3.25rem;
				box-shadow: var(--edge-highlight), var(--shadow-glass);
				border-radius: calc(var(--rounded-corner) + 0.25rem);
				background-color: var(--glass-bg);
				padding: 0.25rem;

				li {
					width: 100%;
					white-space: nowrap;

					a {
						border-radius: var(--rounded-corner);
						text-align: start;
					}
				}
			}

			@media only screen and (max-width: 480px) {
				&:has(summary:not(.circle)) ul {
					inset-block-start: 2.75rem;
				}
			}
		}

		#feed .icon {
			-webkit-mask-image: var(--icon-feed);
			mask-image: var(--icon-feed);

			:root[dir*="rtl"] & {
				transform: scaleX(-1);
			}
		}

		#repo .icon {
			-webkit-mask-image: var(--icon-git);
			mask-image: var(--icon-git);
		}

		#language-switcher .icon {
			-webkit-mask-image: var(--icon-languages);
			mask-image: var(--icon-languages);
		}
	}
}